Type 'Null' is not a subtype of type 'List<int>' in type cast

I’m using flutter null safety. I have not error in console but the images are not showing. I have this error:

======== Exception caught by image resource service ================================================
    The following _CastError was thrown resolving an image codec:
    type 'Null' is not a subtype of type 'List<int>' in type cast
    
    When the exception was thrown, this was the stack: 
    #1      NetworkImage._loadAsync (package:flutter/src/painting/_network_image_io.dart:99:24)
    <asynchronous suspension>
    (elided one frame from dart:async)
    Image provider: NetworkImage("http://.../ebookapp/image/1628743464_mysql.jpg", scale: 1.0)
    Image key: NetworkImage("http://.../ebookapp/image/1628743464_mysql.jpg", scale: 1.0)

code:

class _HomeState extends State<Home> {
      Future<List<ModelEbook>>? getSlider;
      List<ModelEbook> listSlider = [];
    
      @override
      void initState() {
        super.initState();
        getSlider = fetchEbook(listSlider);
      }
    
      @override
      Widget build(BuildContext context) {
        return Scaffold(
          appBar: AppBar(),
          body: Container(
            child: SingleChildScrollView(
              child: FutureBuilder(
                future: getSlider,
                builder: (BuildContext context,
                    AsyncSnapshot<List<ModelEbook>> snapshot) {
                  if (snapshot.connectionState == ConnectionState.done) {
                    return Column(
                      children: [
                        // Slider
                        FutureBuilder(
                          future: getSlider,
                          builder: (BuildContext context,
                              AsyncSnapshot<List<ModelEbook>> snapshot) {
                              if (snapshot.connectionState ==
                                  ConnectionState.done) {
                                //CREATE DESIGN HERE
                                return SizedBox(
                                  height: 27.0.h,
                                  child: Swiper(
                                    autoplay: true,
                                    itemCount: snapshot.data!.length,
                                    itemBuilder: (BuildContext context, int index) {
                                      return GestureDetector(
                                        onTap: () {},
                                        child: Padding(
                                          padding: EdgeInsets.all(10),
                                          child: Stack(
                                            children: [
                                              ClipRRect(
                                                child: Image.network(
                                                 // HERE ERROR
                                                  listSlider[index].photo,
                                                  fit: BoxFit.cover,
                                                  width: 100.0.w,
                                                ),
                                                borderRadius:
                                                    BorderRadius.circular(15),
                                              ),
                                            ],
                                          ),
                                        ),
                                      );
                                    },
                                  ),
                                );
                              } else {
                                return Container();
                              }
                          },
                        )
                      ],
                    );
                  } else {
                    return const Center(
                      child: CircularProgressIndicator(
                        color: Colors.blue,
                      ),
                    );
                  }
                },
              ),
            ),
          ),
        );
      }

I think the error his here but I am not understanding why ? the widget Image.network can take a list of picture ?

child: Image.network(
// HERE CODE
listSlider[index].photo,
fit: BoxFit.cover,
width: 100.0.w,
),